Every time we sit down for a meal out on the deck, a wasp arrives, within minutes. It circles us and inspects the food for a while and then flies away.

The one time the wasp (or at least a wasp, I have no way of knowing if it was the same one) found our food worth eating was back in June when I the food was served with boiled eggs. We could see it cutting off pieces of egg white and flying away with them.

Since then, it comes, it looks, it leaves.

I’m puzzled. Surely the wasp arrives because it has smelled the food, so it must have a good sense of smell. But can’t it detect from the smell whether the food is anything it would actually want to eat?